Diesel engine exhaust gases contain “soot” (particulate matter including fine carbon particles). Under some operating conditions, a considerable amount of soot may be present. The soot, which can be seen as a blackish cloud emanating from an exhaust pipe, is objectionable. Accordingly if it can't be avoided in the combustion process, it needs to be removed.
One manner of removing the soot is by passing the exhaust gases through a filter. A difficulty encountered with the use of a filter is that the filter may become blocked thus interfering with proper engine function by creating too much “back pressure” (i.e. flow restriction) in the exhaust thereby preventing proper outflow of exhaust gases.
Accordingly it is an object of the present invention to provide a filtering apparatus for filtering soot from a diesel engine exhaust which allows at least some gas flow even if a filtering medium associated with the filtering apparatus should become completely blocked.